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This product is no longer available.

No abstract available

Australia marine surveys base map

turned off record due to the lack of metadata, author/custodian and the product itself is un-locatable

The Geological and Oceanographic Model of Australia's Territory (GEOMAT- Harris et al., 2000) developed at Geoscience Australia provides maps indicative of the Australian seabed exposure. GEOMAT v.1 proposed a classification of the Australian under water territory based on sediment mobility induced by distinct processes such as tidal currents and gravity waves (Porter-Smith et al., 2004). GEOMAT v.2 proposed an improved classification of the continental shelf area based on a seabed exposure index (Hemer, 2006). The seabed exposure index was derived from the statistical distribution of the sediment transport rate, which reflected the strength and frequency of the combined wave-current bed shear stress. The bed shear stress was derived from a bottom boundary layer model (SEDTRANS - Li and Amos, 2001), which integrated the combined action of tidal currents (Egbert et al., 1994), oceanic currents (OCCAM : Webb et al., 1998), and gravity waves (AUSWAM - Greenslade, 2001) over a given mean sediment fraction (MARS : Geoscience Australia, 2006).

The Geophysical Processing and Data Access (GPDA) project at Geoscience Australia has undertaken a programme of collating, editing and cataloguing all bathymetry data in the Australian Region. For convenience this region has been loosely defined as extending from 5°S to 80°S and 45°E to 180°E. The contents of the Bathymetric Database consists of four datatypes: - Multibeam Echosounder Data (including LADS) - Singlebeam Echosounder Data - Depths from the digitisation of pre-existing maps - "Depths" derived from remote sensing techniques (and produced grids) The dataset described by this metadata record is the Multibeam Echosounder Dataset. It consists of the soundings of a number of multibeam surveys (170 by April 2007), that vary in size from a few km2 to about 250,000 km2 in size. Data coverage of the defined region is not complete. The datasets were collected by a variety of vessels (Australian and foreign) using a range of sensor systems. As a result the original data exist in a variety of raw data formats on a variety of media. These raw data have been archived in a secure repository at GA. For more details, one should access the metadata records for the individual surveys or the report given in the "Additional Metadata" section of this metadata record. All of the raw data have been imported into the CARIS HIPS application and processed using a common workflow. The processed data have then been exported as GSF "day" files (MBSystem format 121) and stored on Unix directories. These files are easily manipulated using most multibeam data applications

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No abstract available